What is attributable risk in epidemiology?

Attributable risk, also known as the risk difference, is a measure in epidemiology that quantifies the proportion of a disease or health outcome that can be attributed to a specific risk factor. It is calculated by subtracting the incidence rate of the disease in the unexposed group from the incidence rate in the exposed group. This metric helps to assess the public health impact of a risk factor and guides prevention strategies by indicating how many cases could potentially be avoided if the risk factor were eliminated.